A treadmill is an exercise machine that gives the effect of walking or running in a small space by using a belt rotating along an infinite orbit, and is also called a running machine. Demands for the treadmill are ever increasing because the treadmill allows users to walk or run indoors at proper temperatures, regardless of the weather.
Recently, to meet various needs of consumers about the treadmill, a new type of treadmill has been developed.
For example, to reproduce the effect of landing on the ground like in a real track, a treadmill having a slat belt structure is under development. The slat belt structure includes two belts arranged in parallel with each other and a plurality of slats that extend perpendicularly to a rotating direction of the belts and are connected between the two belts. Users exercise in contact with the slats in place of the belts, such that the users may feel like exercising in a real track as compared to exercising on an existing treadmill having a simple belt structure.
However, since the slat belt structure has to bear a load of a user and absorb a shock during a user's exercise, a slat having a strength lower than a predetermined level may be excessively bent or damaged.